I'm Coming Undone

I've had this happen with one of my sims too. I ended up marking him as immortal with MCCC so he wouldn't keep dying hysterical deaths, despite only having one single +2 playful buff. I already had to start a new save file with him because Grim stopped appearing when sims died, urns would just appear. He was the whole reason I had to, he died a hysterical death and despite having a stockpile of death flowers I could do nothing as Grim never appeared to be given a death flower. I tried a game repair, staring a new save in a whole new world, all that and he got hysterical in the new save too.

So if the problem still remains, perhaps try marking your sim as immortal for now so it doesn't keep happening. It is frustrating to have all these weird bugs appearing since IL and the patch.